Sheet feeding apparatus

ABSTRACT

A PHOTOCOPYING MACHINE HAS A STORAGE COMPARTMENT WHICH IS COVERED BY A LID AND CONTAINS A STACK OF COPY PAPER SHEETS LATERALLY CONFINED BETWEEN GUIDE RAILS IN A FEEDING POSITION. ROTATABLY DRIVEN FEED ROLLERS ADVANCE THE TOPMOST SHEET FORWARDLY FROM THE FEEDING POSITION TOWARD AN EXIT THROAT, AND THE TOPMOST SHEET IS SEPARATED FROM THE REMAINDER OF THE STACK BY CORNER SEPARATORS ENGAGING THE FORWARD CORNERS OF THE STACK. FROM THE STACK, THE SHEET MOVES THROUGH THE EXIT THROAT WHICH GUIDES THE INCOMING SHEET INTO THE NIP OF A PAIR OF ROTATING ROLLERS WHICH REMOVE THE SHEET FROM THE COMPARTMENT FOR FURTHER PROCESSING. TO INSERT A FRESH STACK OF SHEETS INTO THE COMPARTMENT, THE FEED ROLLERS AND THE CORNER SEPARATORS ARE SUPPORTED FOR GENERALLY VERTICAL MOVEMENT AND MECHANICALLY CONNECTED TO THE LID SO AS TO MOVE UPWARDLY FROM THE FEEDING POSITION UPON MOVEMENT OF   THE LID TO UNCOVER THE COMPARTMENT. THE FORWARD END OF THE STACK IS ALIGNED WITH THE CORNER SEPARATORS BY A PIVOTALLY SUPPORTED STOP MEMBER WHICH IS MECHANICALLY CONNECTED TO THE LID AND PIVOTALLY MOVED INTO AN UPRIGHT POSITION FOR ENGAGEMENT BY THE STACK UPON THE UNCOVERING MOVEMENT OF THE LID. AFTER THE STACK IS PROPERLY INSERTED, THE LID IS MOVED TO COVER THE COMPARTMENT AND MOVES THE STOP MEMBER FROM THE UPRIGHT POSITION AND MOVES THE SHEET ADVANCING MEANS AND THE CORNER SEPARATORS ONTO THE TOPMOST SHEET OF THE STACK.

United States Patent Inventor [721 Edward W. Engel Northbrook, Ill.

[21] Appl, No. 800,933

[22] Filed Feb. 20, 1969 [45] Patented June 28, 1971 [73] Assignee SCM Corporation New York, N.Y.

[54] SHEET FEEDING APPARATUS 21 Claims, 6 Drawing Figs.

[52] US. Cl 271/61, 271/36 [51] 1nt.Cl B65h 1/04 [50] Field of Search 271/61, 9, 36,42,18,21,19

[56] References Cited UNITED STATES PATENTS 2,893,729 7/1959 Perzentka 271/61X 3,029,074 4/1962 Springer 271/61 3,210,071 10/1965 Rogers etal. 271/21 3,273,883 9/1966 Baronniem. 271/9 3,417,988 12/1968 Springer... 27l/21X Primary Examiner-Joseph Wegbriet Attorneys-Gerald S. Schur and Keith D. Moore ABSTRACT: A photocopying machine has a storage compartment which is covered by a lid and contains a stack of copy paper sheets laterally confined between guide rails in a feeding position. Rotatably driven feed rollers advance the topmost sheet forwardly from the feeding position toward an exit throat, and the topmost sheet is separated from the remainder of the stack by corner separators engaging the forward corners of the stack. From the stack, the sheet moves through the exit throat which guides the incoming sheet into the nip of a pair of rotating rollers which remove the sheet from the compartment for further processing. To insert a fresh stack of sheets into the compartment, the feed rollers and the corner separators are supported for generally vertical movement and mechanically connected to the lid so as to move upwardly from the feeding position upon movement of the lid to uncover the compartment. The forward end of the stack is aligned with the corner separators by a pivotally supported stop member which is mechanically connected to the lid and pivotally moved into an upright position for engagement by the stack upon the uncovering movement of the lid. After the stack is properly inserted, the lid is moved to cover the compartment and moves the stop member from the upright position and moves the sheet advancing means and the corner separators onto the topmost sheet ofthe stack.

' PATENTEU JUN28 um SHEEI 1 [If 4 I v EDWARD w- ENGEL,

PATENTEDqunzsmn 3.588

swam 3 0F 4 I EDWARD W. ENGEL SHEET FEEDING APPARATUS This invention relates to an apparatus for separately advancing a stack of sheets from a feeding position, and more particularly to a photocopying machine having a paper storage compartment containing a sheet feeding apparatus for separating and advancing the topmost sheet from the stack and moving it into the nip of a pair of rotating rollers which remove the sheet from the compartment for further processing. The compartment is normally covered with a lid, and to place a stack of paper in the feeding position, the lid must be moved to uncover the compartment and the apparatus must be moved from the feeding position. In addition, the stack must be aligned with the feeding position so that the stack of sheets may be properly engaged by the sheet feeding apparatus. Finally, the sheet feeding apparatus is moved into engagement with the properly positioned stack and the compartment is covered by the lid in preparation for subsequent operation.

Accordingly, an object of the present invention is to provide a photocopying machine having a sheet feeding apparatus which may be easily moved relative to the feeding position to enable a fresh stack of paper to be placed into the storage compartment in the feeding position for subsequent processing by the photocopying machine.

Another object of the present invention is to provide a photocopying machine having a compartment covered by a lid and containing sheet feeding apparatus for advancing sheets of paper from the feeding position in the compartment, wherein the sheet feeding apparatus may be moved from the feeding position to enable a stack of sheets to be placed in the feeding position solely by moving the lid to uncover the compartment.

An additional object of the present invention is to provide a sheet advancing means for advancing the sheets from the feeding position and a sheet separating means for separating an advancing sheet from the remainder of the stack at the feeding position, wherein the sheet separating means in movable from the feeding position upon movement of the sheet advancing means therefrom to enable a stack of sheets to be placed in the feeding position.

A further object of the present invention is to provide sheet separating means operable in conjunction with a forward stop means for aligning a stack of sheets with the sheet separating means at the feeding position, wherein the sheet separating means is movable from the feeding position and the forward stop means is movable to a position for engagement by a stack of sheets being placed in the feeding position upon movement of the sheet advancing means from the feeding position.

Still other objects, features and advantages of the present invention will be apparent to those skilled in the art from a reading of the following detailed description of a single embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. I is a fragmentary perspective view of a preferred embodiment of a photocopying machine having a sheet feeding apparatus according to the present invention, and showing the topmost sheet being advanced forwardly from the stack;

FIG. 2 is a cross-sectional view of the sheet feeding apparatus taken generally along the lines 2-2 in FIG. 1, illustrating the condition of the apparatus when all of the sheets of paper have been fed from the storage compartment;

FIG. 3 is a view of the sheet feeding apparatus shown in FIG. 2, illustrating the condition of the sheet feeding apparatus when the lid is lifted for inserting a stack of paper into the compartment;

FIG. 4 is a cross-sectional view of the sheet feeding apparatus taken generally along the lines 4-4 in FIG. I, showing a stack of copy paper sheets properly inserted into the compartment with the lid in a raised position;

FIG. 5 is a cross-sectional view taken generally along the lines 5-5 in FIG. 4, illustrating the mechanical connections between the hingedly connected lid and the feed rollers, the corner separators, and the forward stop;

FIG. 6 is a view of the sheet feeding apparatus shown in FIG. 4, illustrating the condition of the sheet feeding apparatus with the stack of sheets properly inserted and the lid covering the compartment.

Referring generally to the FIGS. in the drawings and particularly to FIG. I, there is shown a photocopying machine, generally indicated 11, for copying original documents onto sheets of copy paper. Except as indicated below, the machine 11 is generally of the type described in US. Pat. No. 3,330,179, entitled Automatic Photocopying Machine. The machine 11 includes a housing 13 having an upper storage compartment, generally indicated 15, with an opening, generally indicated 16, which is covered by a lid 17 and contains a stack 19 of copy paper sheets in a feeding position. The sheets are advanced separately from the feeding position and through an exit throat, generally indicated at 21, which guides the incoming sheets into the nip of a pair of cooperating rollers 23, 25. The rollers 23, 25 are mounted on drive shafts, 27, 29 respectively, which are rotatably driven by suitable means, not shown, to remove the sheets from the storage compartment 15 for further processing in the machine 11. The means for rotatably driving the shafts 27, 29 have been omitted from the description, since they form no part of the present invention and are adequately described in the above-mentioned US. patent.

Inside the housing 13, the stack 19 is supported on a substantially horizontal floor 31 of a tray 33 which is supported between two sidewalls 35, 37 to form the storage compartment 15. The sheets forming the stack 19 are laterally confined in the feeding position between two guide rails 39, 41 which are symmetrically opposite and carried by the tray 33. The guide rails 39, 41 serve to align the stack 19 with the nip of the rollers 23, 25 and are laterally movable to accommodate sheets of different widths therebetween. The guide rails 39, 41 may be held in position on the floor 31 of the tray 33 by any suitable means. As more particularly shown in FIGS. 1 and 2, the guide rails 39, 41 have depending lugs 43 extending downwardly through a lateral slot 45 in the floor 31 with heads 47 on the lower end thereof which engage the floor 3] of the tray 33 in a suitable friction fit.

As shown, the topmost sheet 49 is being advanced forwardly from the stack 19 by sheet advancing means, generally indicated 51, including a pair of rubber covered feed rollers 53, 55 which are fixedly mounted on a rotating shaft 57. The shaft 57 is rotatably driven by the drive shaft 27 through a belt drive, generally indicated by 59, which is located at one end of the shafts 27, S5. The belt drive 59, as shown, includes a conventional timing pulley belt 61 extending around timing pulleys 63, 65 which are fixedly mounted on the ends ofthe shafts 27, 57 respectively, although other suitable belt drives may be used, for example a friction belt drive. The belt 61 is maintained taut and the shaft 57 is supported for generally vertical movement in parallel spaced relation to the shaft 27 by arms 69, 71 which are pivotally connected to the drive shaft 27. The weight exerted on the stack 19 by the rollers 53, 55, the shaft 57, and the pulley 65 is generally sufficient to provide the necessary frictional engagement between the rubber-covered rollers 53, 55 and the topmost sheet 49, so as to enable the rotatably driven rollers 53, 55 to forwardly advance the sheet 49. Although only a single belt drive 59 is illustrated in the preferred embodiment, it is to be understood that suitable belt drives may be located at both ends of the shafts 27, 55. In addition, the belt drive 59 could be located at the opposite ends of the shafts 27, 55 instead of as shown in FIG. I. Also, additional weights may be suitably placed on the shaft 57 to increase the frictional engagement between the rubber-covered rollers 53, 55 and the topmost sheet 49.

As the topmost sheet 49 is advanced, the adjacent sheets of the stack 19 move forward due to the frictional contact between the sheets of copy paper. The forward movement of the sheets may be retarded by suitable friction pads 73 placed on the inner aides ofthe guide rails 39,41 in engagement with the sides of the stack I9. To prevent more than one sheet at a time from being fed into the nip of the rollers 23, 25, separator means, generally indicated at 75, are provided to separate the topmost sheet 49 from the remainder of the stack 19. In the preferred embodiment, the separator means 75 are in the form of corner separators 77, 79 which are symmetrically opposite and engage the forward corners of the stack 19. The corner separator 77 includes a lip 81 resting on a corner of the top most sheet 49 and a down-turned forward portion 83, which is more clearly shown in FIG. 5, engaging the forward end of the stack 19. Since the other corner separator 79, engaging the other forward corner of the stack 19, is similar to corner separator 77, identical reference numerals have been placed on similar portions thereof.

Upon advancement of the topmost sheets 49 by the rotatably driven feed rollers 53, 55 the lips 81 of the corner separators 77,79 hold the forward corners of the sheet 49 and cause them to buckle and bend as shown in FIG. 1. As is known, the forward corners continue to bend until the resiliency of the advancing sheet 49 causes the forward cor ners thereof to move over the lips 81 of the corner separators 77, 79, thereby separating the topmost sheet 49 from the remainder of the stack 19. Further advancement of the topmost sheet 49 moves it into the exit throat 21 which, in the preferred embodiment, is formed by an upwardly inclined forward portion 85 of the floor 31 in conjunction with a generally horizontal plate 87 which is suitably attached to the tray 33. The converging exit throat 21 guides the incoming sheet 49 into the nip of the rotatably driven rollers 23, 25 which remove the sheet 47 from the compartment for further processing in the photocopying machine 11.

As the sheets forming the stack 19 are fed from the compartment 15, the stack 19 diminishes and the sheet advancing means 51 move downwardly, with the shaft 57 being received in notches 89, 91 formed in the guide rails 39, 41 respectively. The corner separators 77, 79 are supported for generally verti cal movement so as to maintain engagement with the topmost sheet of the diminishing stack 19. Although the corner separators might be suitably supported for only vertical movement, in the preferred embodiment the corner separators are sup ported for generally vertical movement in an arcuate path by pivotally mounted arms 93, 95. The arms 93, 95 extend along the outer sides of the guide rails 39, 41 and are pivotally mounted on the rearward portion thereof, although the arms 93, 95 might be mounted on suitable independent pivots.

Due to the pivotal mounting of the corner separators 77,79, they move downwardly through an arcuate path, and ac cordingly the forward end of the stack of sheets must be aligned in relation to the arcuate path so as to prevent the corner separators 77, 79 from binding with the lower sheets of the stack 19. Also, it is necessary for the down-turned forward portion 83 of the corner separators 77, 79 to move past the surface of the floor 31 of the tray 33 to enable the lower sheets to be fed from the compartment 15. As shown, the forward portions 83 of the corner separators 77, 79 extend downwardly through openings, 97, 99 respectively, provided in the floor 31 until the lips 81 rest on the floor 31 of the tray 33 after the last sheet of copy paper has been fed from the compartment 15.

When it is desirable to insert another stack 19 of copy paper sheets into the photocopying machine 11, it is first necessary to move the lid 17 covering the opening 16 of the compartment 15. As shown, to enable the compartment 15 to be easily uncovered, the lid 17 is hingedly connected to the machine by a pair of arcuate-shaped brackets 101, 103, each having one end thereof connected to the lid 17 and the other end pivotally mounted on the sidewalls 35, 37. In addition, the sheets advancing means 51, along with the corner separators 77, 79 must be raised upwardly from the feeding position to enable the stack 19 to be placed on the floor 31 of the tray 33. Furthermore, as previously mentioned, the forward end of the stack 19 must be aligned relative to the arcuate path followed by the downwardly moving corner separators 77, 79 so as to prevent the forward edges of the lower sheets of the stack 19 from interfering with the downward movement of the corner separators 77, 79.

In the past, the comer separators 77 79 have been provided with means, usually in the form of a lever, which is manually operated to move the corner separators 77, 79 upwardly from the floor 31 of the tray 33. Once the corner separators 77, 79 have been lifted upwardly, they must be held in the uplifted position while the paper is being placed on the floor 31 of the tray 33. Unless the levers are provided with locking means to hold the corner separators 77, 79 in the uplifted position, the operator must manually hold the corner separators in the uplifted position while placing the stack of sheets between the guide rails 39, 41. Without locking means on the levers, the insertion of the stack of paper between the guide rails 39, 41 is generally a cumbersome and difficult operation due to the presence of the friction pads 73 for engaging the sides of the stack 19. In addition, after the stack has been properly inserted, the corner separators 77, 79 must be unlocked, iflocks are provided, and moved downwardly until the lips 81 thereof engage the forward corner of the stack. Due to the complicated manipulations hereinabove described, such prior art arrangements for placing the stack of paper in the feeding position are usually undesirable.

It has been found that the inconveniences of raising and lowering the corner separators 77, 79 may be eliminated by providing means for enabling them to be moved with the raising and lowering of the lid 17. As shown, the arcuate-shaped brackets 101, 103 are provided with inwardly protruding pins 105, 107 respectively, for engaging the pivotally mounted arms 69, 71 respectively. Upon lifting the lid 17 upwardly to the position shown in FIG. 3, the pins 105, 107 engage the arms 69, 71 respectively and move the sheet advancing means 51 upwardly from the feeding position. The upwardly moving arms 69, 71 and the shaft 57, along with the brackets 101, 103 and the pins 105, 107 serve as lifting means for the corner separators 77, 79. In accordance with the present invention, the arms 93, supporting the corner separators 77, 79 are provided with carrying means in the form of fingers 109, 111 respectively for engagement by the shaft 57, so as to move the corner separators 77, 79 upwardly and downwardly as the lid 17 is raised and lowered.

To align the forward end of the stack with the arcuate path followed by the downwardly moving separators 77, 79, stop means must be provided for engagement by the forward end of the stack being placed on the floor 31 of the tray 33. In addition to properly aligning the forward end of the stack with the feeding position, the stop means must be movable from the path of the forwardly advancing sheet as the sheets are fed from the compartment 15. In the past, stop means have been provided by extending the down-turned forward portions 83 of the corner separators 77, 79 to a length at least equal to the thickness of the stack of sheets being placed on the tray 33. To properly align the forward end of the stack so as to prevent binding, the extended portions 83 had an arcuate configuration which conformed to the arcuate path followed by the downwardly moving separators 77, 79. Other arrangements used in the past have included a forward stop which is mechanically connected to the corner separators 77, 79 but not integral with them. Such a forward stop is often in the form of a vertical post which is located between the corner separators 77, 79 and descends through an opening formed in the floor 31 of the tray 33 as the corner separators 77, 79 move downwardly.

Such prior arrangements are not always desirable because they necessitate a clearance beneath the floor 31 of the tray 33 substantially equal to the vertical length of the stop means. This clearance is necessary for receiving the stop means, whether in the form of an independent vertical post or extensions of the corner separators 77, 79, beneath the floor 31 of the tray 33. Such prior art arrangements necessarily limit the space in the machine 11 available for the paper storage compartment 15, because space must be provided both above and below the floor 31 of the tray 33 for the forward stop means.

Furthermore, the space beneath the tray 33 may be severely restricted by the location of other parts in the photocopying machine, and thus may prevent the stop mans from descending substantially the full vertical length beneath the floor 31 of the tray 33.

As shown, the photocopying machine 11 is provided with a forward stop means, generally indicated at 113, which is movable to and from an upright position for engagement by a stack of sheets in accordance with the raising and lowering of the lid 17. As more particularly shown in FIGS. 2-6, the forward stop means 113 is in the form of a stop member 115 which is located between the corner separators 77, 79 and extends through an opening 117 formed in the inclined portion 85 of the floor 31. The stop member 115 is supported for pivotal movement to and from the upright position by having the lower end thereby fixedly connected by suitable means to a shaft 119 which is rotatably supported beneath the floor 31 of the tray 33 by brackets 121, 123 connected to the bottom side of the floor 31. The shaft 119 extends laterally to one side of the tray 33 and is rotated by a member 125 which, in the preferred embodiment, is in the form of an arm fixedly attached thereto. The arm 125 serves to move the stop member 115 in accordance with the raising and lowering of the lid 17 and has a slot 127 which receives the protruding pin 105 for movement therein.

Although the stop member 115 is pivotally supported in the preferred embodiment by the shaft 117 which is mounted beneath the floor 31 of the tray 33, it could also be pivotally supported by a shaft mounted above the floor 31 of the tray 33. In addition, the stop member 115 could be pivotally moved by another form of mechanical linkage instead of the pin 105 engaging the arm 125 which, in turn, is connected to the shaft 119. For example, a gear linkage could be used wherein a gear mounted on the shaft 119 is driven by another gear or portion thereof connected to the pivotal mounting of the arcuate-shaped bracket 101.

As the lid 17 is lifted to the position shown in FIGS. 3-5, the pin 105 follows an arcuate path and moves along the slot 127 formed in the arm 125 to pivotally move the stop member 115 to an upright position for aligning a stack of sheets in the feeding position in the compartment 15. As more particularly shown in FIG. 3, when the forward stop member 115 is in an upright or generally perpendicular position, it is spaced slightly rearward of the forward down-turned portion 83 of the corner separators 77, 79 to compensate for the arcuate path of the corner separators 77, 79. Accordingly, when a stack of sheets is inserted into the compartment in engagement with the forward stop member 115, as shown in FIG. 4, the lower sheets of the stack are rearward of the down-turned portions 85 of the comer separators 77, 79 to enable them to move downwardly in an arcuate path without binding on the lower sheets of the stack. in addition, since the forward stop member 115 is separate from the corner separators 77, 79 the downturned forward portions 85 need only extend a length suffi' cient to engage the topmost sheets of the stack, and therefor need not extend a substantial vertical distance beneath the floor of the tray.

After the stack of sheets has been placed on the floor 31 of the tray 33 in alignment with the feeding position, the lid 17 is lowered as shown in FIG. 6 so as to cover the opening of the storage compartment and prepare the machine 11 for operation. As the lid is lowered, the pins 105, 107 supporting the sheet advancing means 51 move downwardly through an arcuate path and lower the rubber-covered feed rollers 53,55 onto the topmost sheet of the stack. The corner separators 77, 79, which are supported by the fingers 109, 111 engaging the shaft 57, likewise move downwardly until the lips 81 thereof rest on the corners of the topmost sheet. Further lowering of the lid 17 moves the pin 105 along the arcuate path and in the slot 127 ofthe arm 125, thereby pivotally moving the forward stop member 115 onto the upwardly inclined portion 85 of the floor 31, thus enabling the sheets to be forwardly advanced from the feeding position during subsequent operation of the machine.

When the photocopying machine is again operated for producing copies of original documents, the rubber-covered feed rollers 53, 55 are rotatably driven to advance the topmost sheet 49. Due to the frictional contact between the sheets forming the stacks, the advancement of the topmost sheet tends to move the stack forwardly. Although the friction pads 73 retard the forward movement of the stack, the adjacent topmost sheets move forwardly into engagement with the down-turned portions 83 of the corner separators 77, 79. As previously described, further advancement of the topmost sheet by the rotatably driven rollers buckles and bends the forward corners thereof until the resiliency of the sheet moves the forward corners over the lips 81, thereby separating the topmost sheet from the remainder of the stack. The rotatably driven rollers 53, 55 continue to advance the topmost sheet and move it into the converging exit throat 21. The exit throat 21 guides the incoming sheet into the nip of the rotatably driven rollers 23, 25 which in turn remove the sheet from the storage compartment 15 for further processing.

While only a single embodiment has been illustrated and described, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, it is to be understood that the invention is not to be limited by the illustrative embodiment, but only by the scope of the depending claims.

lclaim:

1. in a photocopying machine, the combination comprising a storage compartment for supporting a stack of sheets in a feeding position from which they may be separately advanced from said compartments, sheet separating means for separating an advancing sheet from the remainder of the stack, said sheet separating means being adapted to engage at least a portion of an edge of an advancing sheet and being supported for movement relative to said feeding position in said storage compartment, said storage compartment having an opening for inserting a stack of sheets into the compartment, a lid for covering said opening of said storage compartment and supported for movement relative thereto, said lid being movable in one direction for uncovering said opening of said storage compartment to enable a stack of sheets to be inserted therein, means operable upon the uncovering movement of said lid for moving said sheet separating means from said feeding position to enable the stack of sheets to be placed in said feeding position, said lid being movable in another direction for covering said opening of said storage compartment, and said means being operable upon the covering movement of said lid for moving said sheet separating means to said feeding position in said compartment.

2. A photocopying machine according to claim 1, wherein said sheet separating means includes a corner separator for engaging the topmost sheet of the stack and being supported for generally vertical movement in said compartment, said means for moving said corner separator from said feeding position including lifting means having a portion thereof supported for generally vertical movement, said lifting means being movable upwardly upon the uncovering movement of said lid and movable downwardly upon the covering movement of said lid, said means further including carrying means for engagement by said lifting means for raising and lowering said comer separator, said carrying means being engaged by said lifting means upon the uncovering of said lid for raising said corner separator to enable a stack of sheets to be placed in said feeding position beneath said comer separator, and

said carrying means being in engagement with said downwardly moving lifting means upon the covering movement of said lid for lowering said corner separator onto the topmost sheet of the stack.

3. In a photocopying machine according to claim 2, said lid being supported for pivotal movement relative to said opening of said storage compartment, said lifting means including a bracket carried by said lid and movable therewith, said lifting means further including shaft means supported in said compartment for generally vertical movement and movable in response to the movement of said bracket, said shaft means being movable upwardly by said bracket upon raising said lid and being moved downwardly by said bracket upon lowering said lid, said carrying means being a finger connected to said corner separator and extending upwardly over said shaft means for engagement therewith, whereby raising said lid moves said shaft means upwardly into engagement with said finger and raises said corner separator to enable a stack of sheets to be inserted thereunder, and lowering said lid moves said shaft means downwardly with said finger in engagement therewith to lower said corner separator onto the topmost sheet of the stack.

4. A photocopying machine according to claim 3, wherein said lifting means includes a pivotally mounted arm supporting said shaft means for generally vertical movement in said compartment, said arm supporting said shaft means being engaged by said bracket for movement therewith, and further comprising a corner separator arm for supporting said corner separator in said compartment, said corner separator arm being pivotally mounted to support said corner separator for generally vertical movement, and said finger being connected to said corner separator arm to enable said comer separator to be moved upwardly and downwardly in accordance with the movement of said lifting means.

5. A photocopying machine according to claim 4, the combination further comprising a guide member for aligning the side of a stack of sheets being inserted into the compartment with said feeding position, said guide member being supported in said compartment and laterally movable for aligning stacks of different widths with said feeding position, and said corner separator arm being pivotally supported on said guide member for lateral movement therewith.

6. A photocopying machine according to claim 1, the combination further comprising stop means for aligning the forward end of the stack of sheets being inserted into the compartment with said feeding position, said stop means being supported for movement to a generally upright position at said feeding position for engagement by the stack of sheets being inserted into the compartment, and moving means operable upon the uncovering movement of said lid for moving said stop means to said generally upright position.

7. [n a photocopying machine according to claim 6, said stop means being separate from said sheet separating means, and said moving means being operable upon the covering movement of said lid for moving said stop means from said generally upright position.

8. Apparatus for advancing sheets from a stack, comprising a substantially horizontal support for supporting a stack of sheets in feeding position from which the sheets may be separately advanced, sheet advancing means for advancing sheets from said feeding position, sheet separating means for separating the advancing sheets from the remainder of the stack, said sheet separating means being supported for movement relative to said feeding position, said sheet advancing means being movable from said feeding position, operating means operable in response to'movement of said sheet advancing means from said feeding position for moving said sheet separating means from said feeding position to enable a stack of sheets to be placed on said horizontal support in said feeding position, said sheet advancing means being movable into engagement with the topmost sheet of the stack in aid feeding position, and said operating means being operable upon movement of said sheet advancing means to said feeding position for moving said sheet separating means into engagement with the topmost sheet of the stack.

9. Apparatus for advancing sheets from a stack according to claim 8, wherein said sheet separating means includes a corner separator for engaging the topmost sheet of the stack and being supported for generally vertical movement, said sheet advancing means including shaft means supported for generally vertical movement, said operating means including carrying means for engagement by said shaft means, and said carrying means being connected to said corner separator for moving said corner separator therewith, whereby upward movement of said shaft means from said feeding position brings said shaft means into engagement with said carrying means and lifts said corner separator from said feeding position to enable a stack of sheets to be placed on said substantially horizontal support in said feeding position, and downward movement of said shaft means enables said carrying means to lower said corner separator into engagement with the topmost sheet in the stack in said feeding position.

10. Apparatus for advancing sheets from a stack according to claim 9, and further comprising a pivotally mounted corner separator arm for supporting said comer separator for generally vertical movement, and said carrying means being a finger connected to said cornerseparator arm and extending upwardly over said shaft means for engagement therewith.

11. Apparatus for advancing sheets from a stack according to claim 10, and further comprising a guide member for aligning the side ofa stack of sheets being placed on said substantially horizontal support with said feeding position, said guide member being supported for lateral movement relative to said feeding position for aligning stacks of different widths with the feeding position, and said corner separator arm being pivotally supported on said guide member for lateral movement therewith.

12. Apparatus for advancing sheets from a stack according to claim 8, and further comprising stop means for aligning a stack of sheets with said feeding position, said stop means being supported for movement to a generally upright position for engagement by a stack of sheets being placed on said horizontal support, and said operating means including moving means operable upon the movement of said sheet advancing means from said feeding position for moving said stop means to said generally upright position.

13. Apparatus for advancing sheets from a stack according to claim 12, wherein said stop means are separate from said sheet separating means, and said moving means being operable upon the movement of said sheet advancing means to said feeding position for moving said stop means from said generally upright position.

14. In a duplicating machine having a paper feed tray with a substantially horizontal floor for supporting a stack of sheets in a feeding position from which the sheets may be separately advanced, stop means supported by said tray for aligning the stack of sheets with the feeding position and sheet separating means carried by said tray for separating an advancing sheet from the remainder of the stack, said sheet separating means being separate from said stop means and movable independently thereof, said sheet separating means being supported for movement relative to said feeding position, and said stop means being movable to an upright position for engagement by the forward end of a stack of sheets being placed on the tray in the feeding position, the improvement comprising:

means for moving said sheet separating means and said stop means relative to said feeding position, said means being operable for moving said sheet separating means from said feeding position and for moving said stop means to said upright position to enable a stack of sheets to be placed on the tray and aligned with the feeding position, and said means being operable for moving said sheet separating means into engagement with the stack in the feeding position and for moving said stop means from said upright position.

15. In a duplicating machine according to claim 14, said sheet separating means including a corner separator for engaging the topmost sheet of the stack, said corner Separator being supported for generally vertical movement relative to the floor of said tray.

16. In a duplicating machine according to claim 15, the combination further comprising a corner separator arm for supporting said corner separator, said corner separator arm being pivotally carried by said tray to support said corner separator for generally vertical movement.

17. In a duplicating'machine according to claim 16, the combination further comprising a guide member for aligning the side of the stack of sheets being placed on the floor of said tray with said feeding position, said guide member being supported by said tray and laterally movable for aligning sheets of different widths with said feeding position, and said corner separator arm being pivotally supported on said guide member for lateral movement therewith.

18. In a duplicating machine according to claim 17, said corner separator including a down-turned portion for engagement by the topmost sheets of the stack in said feeding position, and said floor of said tray having an opening formed in the upper surface thereof for enabling said down-turned portion of said comer separator to extend past the upper surface of said floor upon downward movement of said corner separator.

19. In a photocopying machine, the combination comprising a storage compartment for supporting a stack of sheets in a feeding position from which they may be separately advanced from said compartment, sheet separating means for separating an advancing sheet from the remainder of the stack, said sheet separating means being separate from any means for advancing sheets from the stack and being supported for movement relative to said feeding position in said storage compartment, said storage compartment having an opening for inserting a stack of sheets into the compartment, a lid for covering said opening ofsaid storage compartment and supported for movement relative thereto, said lid being movable in one direction for uncovering said opening of said storage compartment to enable a stack of sheets to be inserted therein, means operable upon the uncovering movement of said lid for moving said sheet separating means from said feeding position to enable the stack of sheets to be placed in said feeding position, said lid being movable in another direction for covering said opening of said storage compartment, and said means being operable upon the covering movement of said lid for moving said sheet separating means to said feeding position in said compartment.

20. In a photocopying machine, the combination comprising a storage compartment for supporting a stack ofsheets in a feeding position from which they may be separately advanced from said compartment, sheet separating means for separating an advancing sheet from the remainder of the stack, said sheet separating means being stationary in the direction of movement of the advancing sheet and being supported for movement relative to said feeding position in said storage compartment, said storage compartment having an opening for inserting a stack of sheets into the compartment, a lid for covering said opening of said storage compartment and supported for movement relative thereto, said lid being movable in one direction for uncovering said opening of said storage compartment to enable a stack of sheets to be inserted therein, means operable upon the uncovering movement of said lid for moving said sheet separating means from said feeding position to enable the stack of sheets to be placed in said feeding position, said lid being movable in another direction for covering said opening of said storage compartment, and said means being operable upon the covering movement of said lid for moving said sheet separating means tosaid feeding position in said compartment.

21. In a photocopying machine, the combination comprising a storage compartment for supporting a stack of sheets in a feeding position from which they may be separately advanced from said compartment, sheet separating means for separating an advancing sheet from the remainder of the stack, said sheet separating means being supported for movement relative to said feeding position in said storage compartment and being movable only in a direction substantially transverse to the direction of movement of an advancing sheet being separated from the remainder of the stack, said storage compartment having an opening for inserting a stack of sheets into the compartment, a lid for covering said opening of said storage comartrnent and supported for movement relative thereto, said rd being movable in one direction for uncovering said opening 

